Much time and expense has been devoted to developing pesticides which together are efficacious for killing a broad spectrum of agricultural, garden, and veterinary pests. Compounds and compositions have been developed for combatting numerous invertebrate pest varieties, for example, in situations ranging from ridding domestic pets of fleas to protecting vast acreages of staple crops from the depredations of numerous species of insects.
For example, active pesticide (e.g. insecticide) ingredients have been developed that are extremely efficacious, including arsenicals, fluorides, dinitrophenols, organothiocyanates, and numerous highly halogenated compounds, to name but a few. See generally Kirk Othmer, Encyclopedia of Chemical Technology, Volume 13, Wiley-Interscience, Third Edition.
Several drawbacks to the use of synthetic pesticides do exist, however, and these stem principally from these substances' deleterious effects, both immediate and long range, on the environment. That is, many synthetic pesticides are extremely persistent (i.e. do not biodegrade easily) and build up high residue levels as repeated seasonal applications are made. Concern arises not only from ecological implications inasmuch as, for example, some insecticides (e.g., parathion) are known to be lethal to animals, but also from other obvious concerns stemming from the dangers of contaminating human food and water supplies inasmuch as many pesticides are known to be toxic to humans in varying degrees depending at least in part, of course, on the levels of pesticide present.
Against this background what is needed is an efficacious pesticide which does not impart persistent residues to the environment and which, at reasonable application levels, is non-toxic to man and animals. Any compound having this highly desirable combination of properties would be particularly useful if, in addition, it exhibited broad spectrum activity (i.e., against as wide a range of invertebrate pests as possible), was easily obtainable, and was cheap to produce. Such active pesticide ingredients are the subject of this invention.
Insecticides which include plant extracts or plant-based ingredients are known, for example, from U.S. Pat. Nos. 4,361,554 to Saunders and 287,701 to Miller. Neither of these patents discloses any specific insecticidal ingredient, however, both alluding only to "extracts" or "infusions". The Saunders plant extract/insecticide is stated to be effective only against insects lacking an exoskeleton. The Miller patent discloses a multi-component composition which includes plant-based ingredients disclosed in very general fashion. Neither patent discloses the specific ingredients disclosed herein or the plant source from which they may be obtained.